Research on Stress & Social Support with PNI, Cancer, HIV & CHD The effect of stress on immune
functioningThe effect of mood onimmune functioningPersonality and CancerSocial Support and immune
functioning

The relationship
between immunocompetence, or one's functional efficacy of immune response, and psychological experiences and
outcomes is central to this topic.

Psychoneuroimmunology
(PNI) involves interest in the biological mechanisms responsible to
specific and general responses of the bio-psycho-social agent. This field
examines both possible ways to stave off or moderate stress along with
assessments of immune system functioning or state.

As we have already
considered, the field of health psychology places
a great deal of stake in explanation and prediction of the
relationship between mental and physiological states. Psychological
tools for 'measuring' psychological states and traits is related to
physiological and behavioural measures of immune activity and health
promoting behaviours.

Methodological Issues

Poole et al. (2015) Consideration of time frame is important in the
study of PNI,
where both acute or short-term stressors as well as
chronic or
long term effects are considered.

As such short term changes in the immune
system function
are measured in conjunction with short term stressors
(e.g.,
daily hassles, sudden events).

Small
fluctuations in the immune system function may be measured
over the
average day as well as over an period of months.

Where such longer term
stressors are considered
(e.g., trait anxiety, workplace stress, marital
problem,
financial challenges, chronic illness or terror).

As pointed out in
Selye's research on stress, longer term
stressors lead to the GAS, including the
reactive resistance
of parallel biological systems. Because of the multiplicity
of responses,
the singular effects of measurements of any specific
response
will be difficult to determine.

Factorial designs are
also used under experimental treatments. Here the so called main and interaction
effects are examined.

The
downfall of making multiple predictions in a given study is:
that the
more statistical relationships examined, the greater
the likelihood that an
erroneous relationship will be established.

In other words, each relationship
between variables is examined
and a decision about whether or not it is thought
to be real is made
based upon the probability that it will be true,
given known
parameters, 95 times out of 100.

Statistical
significance is this level of 05% chance of error,
sometimes placed
more conservatively at 01% chance of error.
While this level may be achieved
there may or may not be a
clinically significant difference
in outcome or change of symptoms or state.

Field
researchoffers the possibility of examining physiological
responses
to real stressors in natural situations. The challenges
here are that cohortand contamination of data by extraneous variables may be more likely. These are expected in cross-sectional
studies and
longitudinal studies, respectively.

Laboratory
research offers a greater degree of
confidence
in making 'cause and effect' attributions about the variables
through
controlled experimental studies.

However, the lack of natural situations may
alter the response
of the individual against their exposure to an known
antigen.

Limitations on
researchers ability to expose healthy people to
pathogens is an ethical
issue that leads to the use of
quasi-experimental or
natural experimental studies
(e.g., natural prevalence, disaster response).

An
Introduction to the Immune System

Antigens
are microorganisms that are foreign to the human body
and may cause
disease (e.g, viruses, bacterial, fungi, parasites). you
tube

Pathogensare referred to as pathogens when they potentially cause death.

Infections
or diseases may be localized,
or situated in
only one area of the body which may also
be focalized
where they send toxins out throughout the body.

They may also be systemic,
affecting the entire body.
Internal systems of attack on these antigens take
various forms,
primarily through the development of specific and acquired immunity.

Lymphocytesare a mainstay in the immune system,
including B-cells, T-cells and NK-cells (natural kills). utube

Immune
system memory maintains small numbers of "B memory cells" that enable the body to create
immunoglobulins and antibodieswhen
re-exposed to an antigen.

Taking about 5 days to produce a strong response the
B-lymphocytes produce antibodies that are specific to that antigen
(e.g., water parasites).

The action of
B-lymphocytes to produce antibodies is aided through
helper T-cells (CD4) which produce cytokines
called
interleukins (e.g., leukin-1, interleukins-2). Suppressor
T-cells (CD8)
work as "off switches" for the immune
system.

Tolerance
to one's own cells usually occurs where antibodies
are not produced against
one's own cells,
except in auto-immune disorders (e.g., arthritis).

Nonspecific
immunity operates through the general response
of swelling and phagocytosis.

How
Immune-System
Function is Measured in PNI Research

Counting cells
is the primary method used for dependent variables in PNI studies.
As such, one's immunocompetence is measured by one or more cell type
counts.

An enumerative
assay is performed to count levels of B-cells, T-cells and NK-cells
to determine a minimal number or varied balance among these white blood
cells.

Function tests are done to asses immunocompetence in action, across time.
These are donein vitro ( in the test tube)
as well as in vivo (in the human body)
for a specified period of time.

In vitro studies will
involve the addition of a mitogen (agent to
increase activity) to a blood sample (e.g., Con A, PHA, PWM), showing greater or
lesser responses under various psychological states or conditions (e.g,
confrontation).

A second common
approach makes use of the NK cell cytotoxic assay
that shows activity of NK cells. Others like the herpesvirus or
Epstein-Barr virus counts may also be used to assess immune
functioning.

Specific Ab responses
may also be made at the infection or injection site.

Research
on Stress, Mood, Social Support & Personality
with PNI, Cancer & HIV

In various studies, the biological has been examined against a host of
psychological and social factors that have shown some impact on immune
functioning. Some such variable examined include: personality traits,
psychological states or moods, acute and chronic stress, social support
and coping styles.

The
Effect of Stress on Immune Functioning

Immunosuppression is often observed in association with experiences of stress. Lazarus &
Folkman (1984) define stress as "an aversive condition in which the demands
of a situation are perceived to be greater than our ability to cope with them
(Poole at al., p. 65) .

Responses
may be observed in as few a five minutes or as long as 5 days. Some
dispositional differences in physiological reactivity have been cited by Poole
et al with respect to cortisol levels and URIs (upper respiratory
infections).

Boscarino
(1997) reports that PTSD Viet Nam vets were more likely to have circulatory, metabolic
digestive or muscular ailments. They were 2.4
times more likely to have these medical problems, effects maintained at 20 year
follow-up.

Poole
et al. also cite studies on Three Mile Island residents, hurricane Andrew
survivors, Gulf War vets, earthquake victims and men and women going through
divorce. Here they point out that:

One
of the challenges of field studies is the lack of control over amount or levelof antigen
exposure. In
controlled experiments on URIs, antigens are often administered through nasal
sprays in viral
challenge studies.

On
the other hand, the impactof intact
social support systems can be examined through field studies, where it
has been found that larger and more diverse social support systems appear to
lessen the likelihood of cold infections (Cohen et al., 1997).

Other
studies cited by Poole et al. have indicated that positive
life events can have a negative impact on immune functioning.